Ileitis Stalks High-Health Herds

Tony M. Forshey DVM

Sun, 1998-02-01 12:00

As more herds strive to achieve higher herd health status in order to improve efficiencies and profits, certain "high health" diseases, like ileitis, become more prevalent.This disease entity has been around for years. The use of new technologies such as multiple-site production, enhanced biosecurity systems and improved vaccination protocols led to eradication of several major diseases. This allowed

As more herds strive to achieve higher herd health status in order to improve efficiencies and profits, certain "high health" diseases, like ileitis, become more prevalent.

This disease entity has been around for years. The use of new technologies such as multiple-site production, enhanced biosecurity systems and improved vaccination protocols led to eradication of several major diseases. This allowed some secondary diseases to gain in importance and become primary classic problems. Ileitis is one of the easier of these diseases to control, especially if you can predict outbreaks.

Ileitis is known by several different names. It is called Porcine Necroproliferative Enteropathy (PNE) in academic circles. It is perhaps more familiarly referred to as "garden hose gut." Ileitis is caused by an organism called Lawsonia intracellularis. The organism lives inside the cells closely associated with the intestinal tract. Clinical signs vary dramatically and often depend on the age of the affected pigs.

The chronic form of this disease often goes undiagnosed. Producers do not notice the diarrhea in a small percentage (5"percent"-10"percent") of the pigs. This form usually occurs in grower pigs 1-2 weeks after arriving at grow-finish facilities. Performance suffers and affected pigs exhibit a watery, dark diarrhea that may or may not show blood. These pigs become what I call "razorbacks" because, if not treated, they will suffer substantial weight loss.

The cost to the producer is high due to very poor feed efficiency and negative daily gains.

The acute form of ileitis is rapidly becoming the most prevalent. Both finisher pigs and replacement breeding stock die suddenly. New gilts and boars in isolation units will often suffer sudden death from ileitis. Again, this is particularly true in well-managed, high- health herds. Necropsy is crucial in order to differentiate this disease from other enteric diseases. Diagnostic tools also include serology and a polymerase chain reaction (PCR) assay on fecal material. Thesetests are limited, but continue to improve.

Severe thickening of the ileum portion of the small intestines along with necrotic tissue inside the lumen of the intestine occurs with chronic ileitis. Acute ileitis displays a hemorrhagic ileum with mucous and small amounts of necrotic tissue present. These pigs often appear pale. The list of differential diagnoses for ileitis includes Hemorrhagic Bowel Syndrome, whipworms, swine dysentery, salmonellosis, gastric ulcers, Colonic Spirochetosis, and Transmissible Gastroenteritis (TGE). The most important steps toward treatment and control of ileitis are sanitation, strict adherence to biosecurity and accurate health records to help predict outbreaks.

Tylan is the only feedgrade antibiotic labeled for prevention and control of ileitis. It works very well, but remember the stressors of the outbreak must be controlled also. Extra-label use of injectables and water medications are often necessary initially in order to have time to add the feed medication. Accurate diagnosis of enteric disease problems is very important in the long-term control program.

Case Study No. 1 We were called to an isolation facility housing replacement gilts for a 1,200-sow unit. The manager reported finding two dead gilts upon arriving at the facility that morning. This facility is a new, double-curtain unit with totally slotted floors, and is being operated all-in, all-out.

This group of gilts had been in the building about 10 days and had been acting fine, according to the manager.

The remainder of these gilts looked normal. Feed consumption appeared normal.

Necropsy of the two gilts showed a slightly thickened ileum with dark mucous and blood present.

Laboratory results revealed a proliferation of the intestinal lining and the Lawsonia intracellularis organisms.

The gilts were placed on Tylan at 100 g/ton of feed for two weeks after the necropsies and tentative diagnosis of acute ileitis was made. There were no other death losses in this group. A control program utilizing feedgrade Tylan on subsequent groups successfully prevented ileitis outbreaks.

Case Study No. 2 Recent groups in a 1,000-head finisher had been experiencing sudden death in a small percentage of pigs. The overall death loss ranged from 1-2"percent" and the majority of these pigs appeared healthy prior to death.

We had not previously necropsied any of these pigs. The producer thought they had died from Streptococcus suis because they were doing well and showed no signs of diarrhea.

The pigs weighed 220 lb., and appeared pale and bloated.

Necropsy results showed the small intestines were very congested and contained a lot of blood and mucous.

The preliminary diagnosis was Hemorrhagic Bowel Syndrome. Laboratory results were negative for Lawsonia organisms. There was no ileum thickening or proliferation.